AUTHOR=Zhou Xujiao , Dai Yiqin , Zhai Zimeng , Hong Jiaxu 

TITLE=WAY-100635 Alleviates Corneal Lesions Through 5-HT1A Receptor-ROS-Autophagy Axis in Dry Eye

JOURNAL=Frontiers in Medicine

VOLUME=8

YEAR=2021

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2021.799949

DOI=10.3389/fmed.2021.799949

ISSN=2296-858X

ABSTRACT=<p><bold>Purpose:</bold> To explore whether 5-HT<sub>1A</sub> receptors are involved in the dry eye disease (DED) mouse model and reveal its underlying mechanism.</p><p><bold>Methods:</bold> A C57BL/6J mouse DED model was established via the administration of 0.2% benzalkonium chloride twice a day for 14 days. Corneal fluorescein sodium staining score and Schirmer I test were checked before, and on days 7, 14, and 21 after treatment. The experiment was randomly divided into control, DED, 5-HT<sub>1A</sub> receptor agonist with or without N-acetylcysteine (NAC) and 5-HT<sub>1A</sub> receptor antagonist with or without NAC groups. The mRNA expression of inflammatory cytokines was measured by reverse transcription-quantitative polymerase chain reaction. Cellular reactive oxygen species (ROS) were detected by 2', 7'-dichlorodihydrofluorescein diacetate assays. Western blot analysis was used to measure the expression levels of autophagic proteins microtubule-associated protein 1 light chain 3 (LC3B-I/II) and autophagy-related gene 5 (ATG5).</p><p><bold>Results:</bold> 5-HT<sub>1A</sub> receptor agonist (8-OH-DPAT) increased corneal fluorescein sodium staining spots and 5-HT<sub>1A</sub> receptor antagonist (WAY-100635) decreased them. Treatment with 8-OH-DPAT was associated with the gene expression of more inflammatory cytokines, such as interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), C-C motif chemokine ligand 2 (CCL2) and C-X-C motif chemokine ligand 10 (CXCL10) compared with treatment with WAY-100635. An increased expression of LC3B-I/II and ATG5 was observed in corneal epithelial cells in the mouse model of DED. 8-OH-DPAT significantly enhanced the expression of LC3B-I/II and ATG5 by disrupting ROS levels. WAY-100635 alleviates autophagy by inhibiting ROS production.</p><p><bold>Conclusion:</bold> Excessive ROS release through 8-OH-DPAT induction can lead to impaired autophagy and increased inflammatory response in DED. WAY-100635 reduces corneal epithelial defects and inflammation in DED, as well as alleviates autophagy by inhibiting ROS production. The activation of the 5-HT<sub>1A</sub> receptor-ROS-autophagy axis is critically involved in DED development.</p>